I was cleaning out my air filter a few days ago and noticed how dark the power steering fluid in the PS reservoir was in my '99 GS400 (on the passenger side by the air filter). In any event, I wanted to get the fluid in the PS reservoir cleared up a bit. Here's what I did:

EDIT: WARNING INFORMATION: Do NOT use "power steering" fluid in your Lexus power steering reservoir. Some automotive manufacturers use a specialized "power steering fluid" in their PS systems, but Lexus power steering systems are designed to use "automatic transmission "fluid (ATF) as the hydraulic fluid. However, you can use any Dexron II or Dexron III ATF (i.e. Toyota ATF) to fill the PS reservoir.

BASIC QUICK CHANGE

Time: about 10 minutes (once you're initially set up)

I ended up doing a partial "quick" change of it by siphoning the PS reservior fluid out (about 7 ounces) with a turkey baster that I had attached a 5" long small vinyl tube described above. As the PS reservoir opening is not very large (about 5/8"), you must use the 1/2" OD or smaller vinyl tubing to get it inserted deep enough to get most of the fluid out. I put the old fluid into a used clear water bottle so I can inspect the fluid.

Once you siphon out most of the fluid in the power steering reservoir, fill it up with new Toyota ATF (or any Dexron II or Dexron III compatible ATF fluid) to the top of the "COLD" line.

To ensure that no air bubbles are in the PS system, you should bleed the PS system. To do so, first, with the engine off, turn the wheel completely to the right, then to the left for 2-3 cycles. Afterwards, turn on the car, then turn the wheel completely to the right and hold it for only 3 seconds, then turn it to the left completely and hold it for only 3 seconds--repeat for 1 more cycle. If possible, do the steering wheel turning on a gravel/dirt surface (if avaialble) so you don't rub your tires down. Inspect your PS reservoir to make sure that there are no bubbles in the fluid--if so, repeat the whole air bleed procedure.

To ensure that all of the new fluid mixes in with the old fluid, you will NEED to drive the car around for a few days before you can do the quick change again. Else, you'll just siphon out all new, unmixed fluid, which defeats the purpose of the change.

NUMBER OF CHANGES

Described above was for 1 quick change, and it does NOT get most of the old fluid out in 1 shot. The total capacity of the PS reservoir is about 1.06 quarts (33.8 oz) (at least for the GS400), and as you can only remove about 7 oz using the above siphon method, you're left with 79% old fluid left. With three quick changes, you'll be at 50% old fluid. And with 5 quick changes, you'll be at 31% old fluid. To feel comfortable, I'm guessing that you will need to quick change out the fluid about 8 times (15% old fluid)--hence my suggestion of getting 2 quarts of ATF. As it was my first time changing it, I will repeat this quick change procedure every week for the next 8 weeks or so, to get incrementally new fluid in the power steering system.

A power steering system fluid flush would get most of the fluid out, but I didnt' want to pay the dealer $90 for something I could easily and cleanly do myself (albeit incrementally). However, if someone wants to post how to do a proper flush of the ATF in the PS system, I would be interested. . .

MISC. NOTES

The removed fluid in the PS reservoir was very dark and had brownish tinge to it--there was no red at all (FYI, the normal ATF color should be a raspberry red color). Obviously, for the dark color of the fluid, it's been in there since the car was new. I've actually now changed the fluid twice (leaving 63% old fluid), and the power steering pump seems incrementally quieter than it had been before. Mind you, the PS pump wasn't loud before, it's just now quieter with the the 2 incremental PS fluid changes. The second siphoned out series fluid is starting to get a little red color (but still rather dark), so that's a good thing--a few more weeks, and I'll get it looking red again. . .

I think some cheap preventative maintenace by changing some fluid in the PS reservoir a bit at a time is much better than leaving the fluid in there for the life of the car--esp. knowing how expensive the power steering pump replacement can be.

I have been doing this same incremental power steering change on my 1993 LS 400.

I initially tried the turkey baster but got frustrated with it not having enough suction to really do the job right.

Something that I think works much better is a gadget called "The Mixmaster" which Wal-Mart has. I think it costs about $3.98. It's primarily designed to measure and mix 2-cycle oil with gasoline for chain saws. It's shaped somewhat like a physician's hypodermic needle and works the same way. It comes with a plastic tube extension that easily fits into the power steering reservoir. (It even fits the tiny opening to the power steering reservoir in my wife's ES 300.) It has measurements on the body to help you determine how much fluid you have withdrawn.

Watch out for the whining sound after you have withdrawn and added fluid. If it occurs, do the bleeding procedure until it stops.

Good info on the Mix-Mizer. I probably would have gotten that part if I had known about it beforehand--but the $2 turkey baster from Safeway works decently enough (and it has 0.25oz increment markings on the side of it).

I was going to attempt a PS fluid flush, but it seemed too messy to do, so I went w/ the easy incremental process instead. I'll get my PS fluid nice and clear in the next few weeks. . .

SeattleGS400, I agree the incremental method is the safest and most idiotproof method for changing both the power steering and auto trans fluid. It's not as "cool" or "hi-tech" as the total flush / total fluid replacement methods, but at least you never read about power system failures or auto tranny failures like you do from time to time from people who try the high tech methods.

The incremental method I use is to buy a 7 foot long, 1/2" outside diameter
piece of vinyl tubing from a hardware store for two or three bucks and just suck up the 7 ounces using my mouth. Then I empty the used fluid into a kitchen measuring cup to measure the amount removed and pour back the same amount of new fluid.

I also agree the safest power steering fluid to use is the Genuine Toyota ATF because it's Toyota tested and approved and Toyota's standards (in regard to reliability and durability) are the highest of any automaker in the world. http://www.saber.net/~monarch/gtatf.jpghttp://www.saber.net/~monarch/gtatf2.jpg Sounds like your local dealer is gouging you on the price
of the Toyota ATF, however, since the RETAIL price is $3.29 a quart and some discount Toyota dealers like Bob Bridge Toyota in Renton, Washinton, will probably sell it to you for 28% off retail. Here's an example of the prices Bob Bridge offered recently on some stuff for my 1992 Toyota pickup:http://www.saber.net/~monarch/bobbridge.JPG

The Toyota stuff is repackaged, just made to higher standards, with a standard Lubrizol Dexron additive package. I'm using Red Line Power Steering Fluid, it's synthetic, and it meets Dexron-II/Dexron-IIE standards. I feel uncomfortable using Dex-III in a power steering system, the additive package isn't friendly to some seals used in PS systems.

Genuine Toyota auto trans fluid has been specifically designed for Toyota
automatic transmissions and has been tested and approved by Toyota
for use in Toyota componets that require a Dexron II or III fluidhttp://www.saber.net/~monarch/atftoy.JPG

You say the Toyota stuff is "repackaged". Does this mean you know
about another SPECIFIC fluid on the market that is chemically identical to
genuine Toyota auto trans fluid? Or are you just speculating that
the Toyota stuff is just a repackaged existing product?

Likewise, do you know about any SPECIFIC additives in genuine Toyota auto
trans fluid that are "not friendly" with certain SPECIFIC seals in
Toyota/Lexus power steering systems?

Genuine Toyota auto trans fluid has been specifically designed for Toyota
automatic transmissions and has been tested and approved by Toyota
for use in Toyota componets that require a Dexron II or III fluidhttp://www.saber.net/~monarch/atftoy.JPG

You say the Toyota stuff is "repackaged". Does this mean you know
about another SPECIFIC fluid on the market that is chemically identical to
genuine Toyota auto trans fluid? Or are you just speculating that
the Toyota stuff is just a repackaged existing product?

Likewise, do you know about any SPECIFIC additives in genuine Toyota auto
trans fluid that are "not friendly" with certain SPECIFIC seals in
Toyota/Lexus power steering systems?

i'm just speculating the Toyota stuff is repackaged, my local Toyota dealer uses Quaker State for ATF. As for the D-III additives, i know from experience Mercedes systems don't take D-III fluid quite well.

Yes, Toyota and Lexus dealer service departments commonly substitute aftermarket fluids and lubes in place of genuine Toyota fluids and lubes because the aftermarket stuff is less expensive for them to buy.
Americans tend to put short term profits ahead of everything else and Toyota can't change the character and culture of Americans. However, I'm glad corporate Toyota offers genuine Toyota fluids and lubes for owners who wish to maintain their cars with the top quality factory original fluids and lubes.

Yes, Toyota and Lexus dealer service departments commonly substitute aftermarket fluids and lubes in place of genuine Toyota fluids and lubes because the aftermarket stuff is less expensive for them to buy.
Americans tend to put short term profits ahead of everything else and Toyota can't change the character and culture of Americans. However, I'm glad corporate Toyota offers genuine Toyota fluids and lubes for owners who wish to maintain their cars with the top quality factory original fluids and lubes.

Originally posted by RA40 I've used one of those pumps that can be used to pump gear oil into the differential. It has a tube on both ends so routing one into the reservior and into a catch bottle is easy. Cost is $5.

Any thoughts on the Mobil 1 ATF in this application?

I used one of those pumps too. Also, anybody got info on Valvoline SynPower Synthetic Power Steering Fluid? I hope its good